Lightweight, hinged self-closing container covers and elastomer springs for use with such covers

ABSTRACT

Lightweight, hinged self-closing container covers using elastomer springs to self-close the cover are provided. Several cover designs having gates that may be circular or non-circular and may occupy up to almost 100% of the surface of the cover are implemented using elastomeric springs placed either on a lower surface of the cover (i.e., inside the container) or on an external surface of the cover. By choosing the material properties of the elastomer, dynamics of the gate behavior may be controlled. The elastomeric springs may be formed and cured in situ or, alternately, may be precast and cured and applied to the covers with adhesive or the like when the cover is attached to the container. The gates may be implemented with a toggle action when required.

RELATED APPLICATIONS

This application is a Continuation-in-Part application of U.S. patentapplication Ser. No. 14/226,898 for LIGHT WEIGHT, HINGED SELF-CLOSINGCONTAINER COVERS AND COMBINATION FLEX-TORSION SPRINGS FOR USE WITH SUCHCOVERS filed Mar. 27, 2014 and included herein in its entirety byreference.

FIELD OF THE INVENTION

The invention pertains to container covers and, more particularly, tolightweight, self-closing covers having frangible seams surroundingreclosable gates that occupy a large percentage of the area of thecontainer cover and are supported by elastomer springs.

BACKGROUND OF THE INVENTION

For many years, manufacturers of cans, particularly aluminum beveragecontainers have searched for a way to replace pull tab openingmechanisms ubiquitous in the beverage industry. Variations of pull tabopening mechanisms are universally used throughout the world but havetwo primary deficiencies. First, with some pull tab designs, the tab mayfall into the beverage container and potentially become a swallowinghazard. Second, once opened, pull tab opening mechanisms are not easilyresealed. Beverages, particularly carbonated beverages like beer andsoft drinks, rapidly lose their effervescence as the entrained carbondioxide is released from the beverage and passes into the airsurrounding the beverage container.

Additionally, pull tab opening mechanisms typically require at leastsome finger/hand strength to open the container. The opening process maypresent difficulties to potential users who do not possess sufficientfinger/hand strength.

Also, pull tab tops of the prior art require a quantity of metal,generally aluminum, that might be reduced in a better design, and areprocess intensive in their manufacture.

In the previously filed application included by reference, covers havingrelatively large reclosable gate openings (i.e., gate openings occupying90% or more of the cover including chuck walls) have been disclosed.These covers rely on metallic combination flex-torsion springs to effectopening and reclosing thereof. These combination flex-torsion springsprovide resistive and restoring forces through a combination of flexingand torsional movements. The disadvantages include cost of manufacturingand the complexity of assembly of covers that include them.

It would, therefore, be desirable to create an easily openable containercover having a large gate, and that also eliminates the possibility ofany portion of the pull tab opening mechanism from detaching from thecan and falling into the contents. It would further be desirable tocreate a reclosable cover so as to trap carbon dioxide from escapingfrom the beverage into the surrounding air. It would be still furtherdesirable to make the container top lightweight to minimize the amountof metal needed to form the top and any associated spring. It would befurther desirable to provide self-closing covers using elastomer springsplaced either internally (i.e., within the container), or externally onthe outside cover surface.

SUMMARY OF THE INVENTION

In accordance with the present invention there are provided lightweight,covers for containers having self-closing gates or dome areas that areoperatively connected to outer portions of the cover by an elastomerspring. Such elastomer springs may be formed from resilient materialshaving the necessary properties including percentage of elongation, curemethods, cure times, etc.

A unique tri-fold seam including a frangible seam portion forms a flangethat works cooperatively with the elastomer spring to implement threemodes of operation of the openable gates. In a first mode, after thegate is initially opened by downward directed pressure, for example atap on the dome or gate by the heal of the palm of a user's hand, thegate returns to a reclosed orientation. Further downward pressure on thegate pushes it further into the container to which the novel cover isattached whereat a toggle operation locks the gate in the open position.An action such as swirling the container contents against the gate,overcome the toggle and the gate again returns to a reclosedorientation. Finally, if the gate is pushed even further downward, thetoggle mechanism is defeated and the elastomer spring is forced past itselastic limit and the gate remains in a permanently open orientation.The novel covers in accordance with the invention may be fabricated tobe compatible with current production equipment and practices. The novelcovers eliminate the pull tab construction of the prior art and allow acomparable container to be produced using less material than prior artcontainers. Multiple designs for elastomer springs are also provided,including extremely narrow designs that allow the gate to occupy nearly100% of the cover area inside or outside the chuck walls.

It is, therefore, an object of the invention to provide a lightweight,reclosable cover for a container that utilizes a spring formed from anelastomer material.

It is another object of the invention to provide a lightweight,reclosable cover for a container that utilizes an elastomer spring toeffect reclosing.

It is a further object of the invention to provide a lightweight,reclosable cover for a container wherein the elastomer spring may beeither disposed on an outer surface or disposed adjacent an innersurface of the cover.

It is an additional object of the invention to provide a lightweight,reclosable cover for a container that utilizes an elastomer spring toprovide three modes of operation of the gate: a first mode allowing thegate to close upon release of the downward pressure upon it; a secondmode wherein the gate remains open when the downward pressure isreleased but recloses when tapped or otherwise stimulated; and a thirdmode where the gate remains permanently open.

It is a further object of the invention to provide a lightweight,reclosable top for a container wherein the gate occupies 90% or more ofthe cover area inside or outside the chuck walls.

It is a still further object of the invention to provide a lightweight,reclosable top for a container that may be formed using smaller amountsof aluminum or other material than container covers of the prior art.

It is yet another object of the invention to provide a lightweight,reclosable top for a container that may be attached to containers usingexisting machinery without modification.

BRIEF DESCRIPTION OF THE DRAWINGS

Various objects, features, and attendant advantages of the presentinvention will become more fully appreciated as the same becomes betterunderstood when considered in conjunction with the accompanyingdrawings, in which like reference characters designate the same orsimilar parts throughout the several views, and wherein:

FIG. 1A is a side elevational, cross-sectional, schematic view of acover using an elastomer spring in accordance with the invention;

FIG. 1B is an enlarged view of a portion of the cover of FIG. 1A;

FIG. 1C is an enlarged view of another portion of the cover of FIG. 1A;

FIG. 1D is a top plan, schematic view of the cover of FIG. 1A;

FIG. 1E is a partial side perspective, cross-sectional, schematic viewof the cover of FIG. 1A;

FIGS. 2A-2H are partial side elevational views of the top of FIG. 1A invarious stages of initial opening and subsequent self-closing;

FIG. 3A is a side elevational, cross-sectional, schematic view of acover using an elastomer spring disposed on an external chuck wall inaccordance with the invention;

FIG. 3B is an enlarged view of a portion of the cover of FIG. 3A;

FIG. 3C is an enlarged view of another portion of the cover of FIG. 3A;

FIG. 3D is a top plan, schematic view of the cover of FIG. 3A;

FIG. 3E is a partial side perspective, cross-sectional, schematic viewof the cover of FIG. 3A;

FIGS. 4A-4D are partial side elevational views of the top of FIG. 3A invarious stages of initial opening and subsequent self-closing;

FIG. 5A is a side elevational, cross-sectional, schematic view of acover using an internal elastomer spring disposed on an inner surface ofthe cover;

FIG. 5B is an enlarged view of a portion of the cover of FIG. 5A;

FIG. 5C is an enlarged view of another portion of the cover of FIG. 5A;

FIG. 5D is a bottom plan, schematic view of the cover of FIG. 5A;

FIG. 5E is a partial side perspective, cross-sectional, schematic viewof the cover of FIG. 5A;

FIGS. 6A-6E are partial side elevational views of the top of FIG. 5A invarious stages of initial opening and subsequent self-closing;

FIG. 7A is a side-elevational, schematic view of an external flushelastomer spring that may be pre-formed and cured;

FIG. 7B is a side-elevational, schematic view of the elastomer spring ofFIG. 7A with adhesive applied to respective left and rightadhesive-receiving walls;

FIGS. 7C-7L show a series of partial side elevational, cross-sectional,schematic views of a portion of a container cover having the elastomerspring of FIG. 7A installed with the gate at various stages of openingand re-closing;

FIG. 8A is a side elevational, cross-sectional, schematic view ofanother internal elastomer spring;

FIG. 8B is a side elevational, cross-sectional, schematic view of aself-closing container using elastomer spring of FIG. 8A to provide therestorative force for the reclosing;

FIGS. 8C and 8D, show detailed partial views of flange portions of thecover of FIG. 8B;

FIG. 8E is a bottom plan, schematic view of the container cover of FIG.8B;

FIG. 8F is a bottom, perspective, schematic view of the cover of FIG.8E;

FIG. 8G is an enlarged detail of a portion of the cover of FIG. 8F.

FIG. 8H is a partial side perspective, cross-sectional, schematic viewof the cover of FIG. 8A;

FIGS. 8I-8M show a series of side elevational, cross-sectional,schematic views illustrating five sequential steps involved in openingand subsequently re-closing the container cover of FIGS. 8B-8G;

FIGS. 9A-9F show detailed side elevational, cross-sectional, schematicviews of the flange region of the container cover of FIGS. 8B-8G invarious stages of opening and closing, including a toggle mode;

FIG. 10A is a top plan, schematic view of a cover having a center domedexternal elastomer hinge;

FIG. 10B is a side elevational, cross-sectional, schematic view of thecover of FIG. 10A;

FIG. 100 is a partial side elevational, cross-sectional, schematic viewa portion of the cover of FIG. 10B;

FIG. 10D is a side perspective, view of the cover of FIG. 10A;

FIG. 10E is a side elevational, cross-sectional, schematic view of thecover of FIG. 10B but with the cover crimped to side walls of acontainer;

FIG. 10F is a side elevational, cross-sectional, schematic view of thecover of FIG. 10A in an unopened state;

FIG. 10G is a side elevational, cross-sectional, schematic view of thecover of FIG. 10F in a partially open state;

FIG. 10H is a side elevational, cross-sectional, schematic view of thecover of FIG. 10F further open than shown in FIG. 10G;

FIG. 10I is a side elevational, cross-sectional, schematic view of thecover of FIG. 10F even further open than shown in FIG. 10H;

FIG. 10J is a side elevational, cross-sectional, schematic view of thecover of FIG. 10F with the cover automatically re-closed; and

FIG. 10K is a side elevational, cross-sectional, schematic view of thecontainer tilted to a drinking position with the upper lip of a drinkerapplying inward pressure against the center domed elastomer cushionhinge.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention provides for lightweight, reclosable containertops that utilize elastomer springs to allow the cover of the containerto self reclose once it has been initially opened. Elastomer springsfunction in manners similar to the combination flex-torsion springs thatare described in detail in my previous U.S. patent application Ser. No.14/226,898 included herein by reference.

There are many advantages in forming the necessary springs from anelastomer material and not from metal as in the prior art flex-torsionsprings described and claimed in my previous work. First, elastomersprings are lighter in weight than metal combination flex-torsionsprings while providing the same functionality. In addition, elastomersprings are significantly less expensive than their metalliccounterparts. Also, assembly time is typically shorter compared toassembly time for covers with metallic combination flex-torsion springs.There may be a slight safety advantage if a metallic combinationflex-torsion spring should fail and become disconnected from thecontainer top.

Technically, elastomers are polymers with viscoelasticity (i.e.,“elasticity”). These materials typically exhibit low values of Young'smodulus as well as high failure strain compared with other materials.The term elastomer, derived from elastic polymer, is often usedinterchangeably with the term “rubber”. Each of the monomers which linkto form the elastomers is usually made of carbon, hydrogen, oxygenand/or silicon. Elastomers are amorphous polymers existing above theirglass transition temperature, so that considerable segmental motion ispossible.

Elastomers or elastomer materials have several physical properties thatmust be evaluated to determine their suitability for use as materialfrom which to form elastomer springs.

First is cure shrinkage percentage (%). Cure shrinkage % for thesematerials may range from a fraction of one percent to what the industrycalls “unmeasurable.” It is absolutely essential that an elastomericmaterial from which springs are formed exhibits a sufficient shrinkagepercentage such that an elastomer spring is able to pull a gate portionof a container cover back to the self-closed position with enough forceto create a complete seal between mating flanges (i.e., fullyself-closed). If the elastomer does not shrink when cured then theweight of the gate will prevent complete self-closing.

Another physical property that must be considered is adhesion strength.Container covers, especially those designed for the food and beverageindustry typically are formed from aluminum having a protective coating.A good bond between the elastomer spring and the coated aluminum surfaceis necessary. The bond must be strong, generally far stronger than theelastomer material itself. Such a bond is similar to a welded joint insteel. A weld applied to steel is typically far stronger than the steelitself. This may be illustrated by the facts that a single edge razorblade will easily cut through an elastomer spring but will not typicallybe able to scrape the adhesive bond away from the surface of the coatedaluminum. An etchant may be mixed with the elastomer to increase thestrength of the bond.

Another mechanical property of the elastomer that must be considered inchoosing an elastomer from which to form elastomer springs is percentelongation. Percent elongation is a measurement that represents how muchan elastomer can be elongated or stretched before it comes to a ratherabrupt stop. For example, an elastomer with a 1000% elongationspecification means that particular elastomer can elongate (i.e.,stretched) ten times its original cured length before the elongationprocess abruptly stops.

Finally, the tear strength for the elastomer must be considered. Tearstrength becomes important after the elongation limit has been reachedand defines the typically far greater force required to physically tearthe cured elastomer than the force required to stretch the elastomer toits elongation limit.

Cure time is also important, especially if elastomer springs are to beapplied to container covers in a high speed production environment.

It will be recognized that properties other than these four propertiesdiscussed above may also be important for a specific elastomer materialor for a specific geometry of a particular elastomer spring.

One material found suitable for forming elastomer springs for use withself-closing container covers is Catalog Number US-SRB-201-HE fast curesilicone rubber parts binder provided by Silicone Technologies ofOgdensburg, N.Y. USA. The US-SRB-201-HE material is intended forapplications demanding very high elongation (over 1000%). When cured,the elastomer resists weathering, ozone, moisture, UV and hightemperatures. Further, US-SRB-201-HE works well in manual and automaticdispensing equipment.

Another material found suitable for constructing elastic polymer springsor hinges suitable for use with self-closing covers is a heat curedsilicone adhesive, Catalog Number RTV-6445 provided by GE BayerSilicones (now part of Momentive Performance Materials headquartered inColumbus, Ohio USA). RTV-6445 is a heat cured silicone elastomer havingapproximately a 625% elongation limit.

It will be recognized by those of skill in the polymer arts thatnumerous other materials exist and any suitable material may besubstituted for the materials cited for purposes of disclosure.Consequently, the patent is not considered limited to the materialschosen for purposes of disclosure. Rather, the patent is intended toinclude any suitable elastomers from which the elastomer springs, inaccordance with the invention, may be formed.

As described hereinbelow, an elastomer spring may be placed on anexternal surface of a cover or, alternately, the elastomer spring may beplaced on or adjacent to an inner surface of the cover.

Referring first to FIG. 1A, there is shown a side elevational,cross-sectional, schematic view of a cover having an external elastomerspring in a “button top” configuration in accordance with the invention,generally at reference number C1.

Cover C1 is shown before attachment to a container represented bypartial container side structure 118 a, 118 b. Cover C1 is shown withits gate in a sealed (i.e., unopened) state. Further, cover C1 is asimplified design used to illustrate the operation of the elastomerspring. More complex covers using other elastomer springs are describedand discussed in more detail hereinbelow.

Cover C1 consists of a seaming panel 102 (best seen in FIG. 1D)surrounding a central gate or dome 108. Seaming panel portions 102 a,102 b have respective distal ends 104 a, 104 b that are adapted forattachment to upstanding walls 118 a, 118 b of a container and adaptedto form a peripheral seal, not shown. Note that any container or portionthereof shown or discussed herein forms no part of the present inventionand is shown and/or discussed only to better describe cover C1.

In the cross-sectional view of FIG. 1A, distal ends 104 a, 104 b,seaming panel portions 102 a, 102 b, panel portions 120 a, 120 b,countersinks 116 a, 116 b, and flanges 106 a, 106 b are labeled forpurposes of discussion. However, cover C1 is typically a circularstructure best seen in FIG. 1D and distal end 104, seaming panel 102,panel 120, countersink 116, and flange 106 represented respectivelythereby are continuous, circular structures, at least until the initialopening of gate 108.

Distal ends 104 a, 104 b of seaming panel portions 102 a, 102 b,respectively, form what is commonly known in the industry as a curl.Proximal ends, not specifically identified, of seaming panel portions102 a, 102 b are each contiguously connected to respective panelportions 120 a, 120 b. Panel portions 120 a, 120 b terminate inrespective countersinks 116 a, 116 b. Another panel portion 126 a, 126 bjoin respective countersinks 116 a, 116 b to respective tri-foldseparable seams forming flanges 106 a, 106 b, respectively. Flanges 106a, 106 b are shown in detailed portions 122 a 122 b in FIGS. 1B and 1C,respectively, and are discussed in more detail hereinbelow.

A gate or dome 108 occupies the central region of cover C1 surrounded byseaming panel 102 (FIG. 1D). Gate 108 in the simplified cover C1occupies approximately 80% or more of the top surface of cover C1. Itwill be recognized that the novel construction may be implemented ingate or dome 108 ranging in size from substantially 100% of the coversurface down to very small sizes creating small apertures.

Chuck walls 114 a, 114 b define respective countersunk regions 116 a,116 b.

Panel sections 126 a, 126 b are surrounded by countersinks 116 a, 116 band fill the space between countersinks 116 a, 116 b and respectivetri-fold flanges 106 a, 106 b.

An external button top elastomer spring 112 is disposed substantiallyatop tri-fold flange 106 a and connecting panel portion 126 a and gate108. Spring 112 provides support and closure force for gate 108 afterthe gate has been initially opened.

Referring now also to FIGS. 1B and 1C, there are shown enlarged drawingsof portions 122 a, 122 b of flanges 106 a, 106 b respectively. Ofparticular interest is the coined frangible seam 110 a, 110 b formed inflanges 106 a, 106 b. Frangible seam 110 a, 110 b defines a tear linecompletely around gate 108 that allows separation of gate 108 from panel126 as gate 108 of cover C1 is “opened”. Frangible seams 110 a, 110 bare typically formed using a coining process. However, it will berecognized by those of skill in the art that alternate formationprocesses may be utilized.

Referring now also to FIGS. 1D and 1E, there are shown top planschematic and partial side perspective schematic views, respectively ofcover C1 of FIGS. 1A, 1B, and 1C. In FIGS. 1D and 1E, the relationshipof each of the components and features described hereinabove withrespect to FIGS. 1A, 1B, and 1C may readily be seen. The width of gate108 is represented by arrow 128. In FIG. 1E, the relationship ofexternal button top elastomer spring 112 to the remainder to thestructure of cover C1 may readily be seen.

Referring now also to FIGS. 2A-2H, there are shown a series of sideelevational, cross-sectional, schematic views of a cover having anexternal elastomer spring in an external “button top” configuration ofFIG. 1A in various stages of opening and self-closing. Table I provides,a percentage of elongation of elastomer spring 112 and an angle ofrotation of gate 108 relative to a horizontal reference line 130connecting an upper point of frangible seam points 110 a, 110 b. Angleof rotation is indicated by reference number 138.

TABLE I Figure % Elongation Angle of Gate Rotation FIG. 2A 0.1% −5° FIG.2B 0.5% −10° FIG. 2C 200%  −20° FIG. 2D 300%  −30° FIG. 2E 200%  10°FIG. 2F 0.3% 20° FIG. 2G 0.2% 8° FIG. 2H 0.0% 0°

In FIG. 2A, a downward directed pressure has been exerted on gate 108 asshown by arrow 132. In response to this downward pressure, frangibleseam 110 a has ruptured and the remainder of flange 106 a has moveddownward carrying gate 108 downward into what would be an interiorregion of a container, not shown, to which cover C1 would be attached.Reference number 134 denotes the gap between the edges of frangible seam110 a. As may be seen by the relationship of lines 138 and referencehorizontal line 130, gate 108 has rotated approximately −0.5°. Thismotion has caused elastomer spring 112 to be slightly elongated(approximately 0.1%). Frangible seam portion 110 b has not yet ruptured.

In FIG. 2B, continued downward directed force on gate 108 has causedfurther downward travel of the remainder of flange 106 and gate 108.Consequently, gap 134 has widened. Gate 108 has now rotatedapproximately −10°. The continued downward movement has furtherelongated elastomer spring 112 by approximately 0.5%. Frangible seamportion 110 b has still not begun to rupture.

In FIG. 2C continued downward directed force on gate 108 has caused evenfurther downward travel of the remainder of flange 106 and gate 108. Gap134 has now widened even further. Gate 108 has now rotated approximately−20° and elastomer spring 112 has been elongated approximately 200%.Frangible seam portion 110 b has still not begun to rupture.

In FIG. 2D, frangible seam 110 b has ruptured and the remaining portionof flange 106 b has started to travel downward as indicated by gap 136.Gate 108 is now rotated to a 30° angle relative to reference horizontalline 130. Gap 134 has stopped widening. Elastomer spring 112 has nowbeen elongated to its maximum extent (i.e., approximately 300%).

In FIG. 2E, the dynamics of the movement of gate 108 changes. Oncefrangible seam portion 110 b has ruptured, elastomer spring 112contracts and begins to pull the remaining portion of flange 106 aupward thereby closing gap 134. The elongation of spring 112 shrinks toapproximately 200° and the angular orientation of gate 108 shifts,moving from −30° in FIG. 2B to a 10° orientation in FIG. 2E. However, asthe left edge of gate 108 rises, the right edge of gate 108 continuesdownward.

In FIG. 2F, frangible seam portion 110 a has returned to its original,unopened position and gap 134 has shrunk to substantially zero. Gap 136has opened as the right edge of gate 108 continues downward to create anangle of rotation of approximately 20°. The elongation of elastomerspring 112 has dropped to approximately 0.3%.

In FIG. 2G, an upward directed restoring force 140 is exerted on gate108 by elastomer spring 112. In response to this upward directed force140, the right edge of gate 108 has started to move upward. In FIG. 2G,the elongation of elastomer spring 112 has shrunk to approximately 0.2%and the rotation angle of gate 108 has been reduced to approximately 8°.

In FIG. 2H, cover C1 has completely reclosed and substantially resealedas both portions of the frangible seam 110 a, 110 b have reclosed. Theelongation of elastomer spring 112 has become zero (i.e., no elongation)and the angle of rotation of gate 108 has also become zero. Line 138 hasbecome coincident with horizontal reference line 130.

In the formation process of elastomer springs (e.g., elastomer spring112), elastomer shrinkage during the curing process creates an importantgate closing bias in the spring. This bias is sufficient to support theweight of a severed gate and hold that gate firmly in a tightly closedposition. A typical shrinkage during curing is approximately 0.05%, aseemingly small amount but sufficient to provide the necessary force tohold a severed gate in a tightly closed condition. It will be recognizedthat elastomer raw materials having different curing shrink rates may bechosen for different spring designs and placements. Consequently, theinvention is not considered limited to a particular cure shrinkage rate.Rather, the invention is intended to include any suitable cure shrinkagerate in addition to the approximately 0.05% chosen for purposes ofdisclosure.

It will be recognized that operation of the opening and self-reclosingof gate 108 as shown in FIGS. 2A-2H and described in the attendingdescriptions is controlled by the design of cover C1. The primarycontrol over the function of gate 108 is the material choice forelastomer spring 112. In this example, an elastomer having a maximumpercentage of elongation of 300% has been chosen. In FIG. 2D, themaximum elongation is reached. Consequently, no further downward travelof the left edge of gate 108 is possible and the downward directed force132 is transferred to the right edge of gate 108 thereby causingfrangible seam portion 110 b to rupture. As the right edge of gate 108is freed, elastomer spring 112 immediately begins contracting and beginspulling the left edge of gate 108 upward until the right edge of gate108 is finally returned to approximately its unopened position andfrangible seam portion 110 a is closed.

If a material with a higher percentage of elongation (i.e., >300) hadbeen chosen, the downward travel of the left edge of gate 108 could havebeen deeper into an interior region of the container to which cover C1was attached. The greater downward travel could allow splashing of thecontainer contents.

This performance is achieved by the choice of elastomer, specificallythe percentage of elongation.

Referring now also to FIG. 3A, there is shown a side elevational,cross-sectional, schematic view of a cover having an external elastomerspring disposed in a chuck wall in accordance with the invention,generally at reference number C2.

Cover C2 is shown before attachment to a container, not shown, and in asealed (i.e., unopened) state represented by partial sides 318 a, 318 b.Further, cover C2 is a simplified design used to illustrate theoperation of the elastomer spring disposed in a chuck wall. Additionalcovers using other elastomer springs and spring configurations aredescribed and discussed in more detail hereinbelow.

Cover C2 consists of a seaming panel 302 (best seen in FIG. 3D)connected to a sloping panel 320 surrounding a central gate or dome 308.Seaming panel portions 302 a, 302 b have respective distal ends 304 a,304 b that are adapted for attachment to upstanding walls 318 a, 318 bof a container and adapted to form a peripheral seal, not shown. Notethat any container or portion thereof shown or discussed herein forms nopart of the present invention and are shown and/or discussed only tobetter describe cover C2. While in the cross-sectional view of FIG. 3A,seaming panel portions 302 a, 302 b, distal ends 304 a, 304 b, and panelportions 320 a, 320 b are labeled for purposes of discussion, cover C2is typically a circular structure best seen in FIG. 3D and seaming panel302, distal end 304 and panel 320 represented respectively thereby arecontinuous, circular structures, at least until initial opening of gate308.

Distal ends 304 a, 304 b of seaming panel portions 302 a, 302 b,respectively form what is commonly known in the industry as a curl.Proximal ends, not specifically identified, of seaming panel portions302 a, 302 b each connect to respective sloping panel portions 320 a,320 b that terminate in respective tri-fold separable seams formingflanges 307 a, 307 b, respectively located in chuck walls orcountersinks 306 a, 306 b. Flanges 306 a, 306 b are shown in detailedportions 322 a 322 b in FIGS. 3B and 3C, respectively, and are discussedin more detail hereinbelow.

A gate or dome 308 occupies the central region of cover C2 surrounded bytri-fold seam 316 (FIG. 3D). Dome 308 in the simplified cover C2occupies approximately 80% or more of the top surface of cover C2. Itwill be recognized that the novel construction may be implemented ingate or dome 308 ranging in size from substantially 100% of the coversurface down to very small sized apertures.

An external elastomer spring 312 is disposed substantially in a chuckwall forming a portion of tri-fold flange 306 a connecting panel portion320 a and gate 308. Elastomer spring 312 provides support and closureforce for gate 308 after the gate has been opened.

Referring now also to FIGS. 3B and 3C, there are shown enlarged drawingsof portions 322 a, 322 b of flanges 306 a, 306 b respectively. Ofparticular interest is the coined frangible seam 310 a, 310 b formed inflanges 306 a, 306 b. Frangible seam 310 a, 310 b defines a tear linecompletely around gate 308 that allows separation of gate 308 from panel320 as gate 308 of cover C2 is “opened”. Frangible seams 310 a, 310 bare typically formed using a coining process. However, it will berecognized by those of skill in the art that alternate formationprocesses may be utilized.

Referring now also to FIGS. 3D and 3E, there are shown top planschematic and partial side perspective schematic views, respectively ofcover C2 of FIGS. 3A, 3B, and 3C. In FIGS. 3D and 3E, the relationshipof each of the components and features described hereinabove withrespect to FIGS. 3A, 3B, and 3C may readily be seen. The width of gate308 is represented by headed line 328. In FIG. 3E, the relationship ofexternal chuck wall elastomer spring 312 to the remainder to thestructure of cover C2 may readily be seen.

Referring now also to FIGS. 4A-4D, there are shown a series of sideelevational, cross-sectional, schematic views of a cover C2 having anexternal elastomer spring in the external chuck wall configuration ofFIG. 3A in various stages of opening and self-closing. Table IIprovides, a percentage of elongation of elastomer spring 312 and anangle of rotation of gate 308 relative to a horizontal reference line330 connecting an upper point of frangible seam points 310 a, 310 b.Angle of rotation is indicated by reference number 338.

TABLE II Figure % Elongation Angle of Gate Rotation FIG. 4A  0.0% 0°FIG. 4B  150% 6° FIG. 4C   10% 6° FIG. 4D 0.05% 0°

FIG. 4A shows gate prior to rupturing of frangible seam 310 a, 310 b andbefore any significant elongation of elastomer spring 312. Horizontalreference line 330 is still level.

In FIG. 4B, a downward directed pressure has been exerted on gate 308shown by arrow 332. In response to this downward pressure 332, frangibleseam 310 a has ruptured and the remainder of flange 306 a has moveddownward carrying gate 308 downward into what would be an interiorregion of a container, not shown, to which cover C2 would be attached.Reference number 334 denotes the gap between the edges of frangible seam310 a. As may be seen by the relationship of lines 338 and referencehorizontal line 330, gate 308 has rotated approximately 6°. This motionhas caused elastomer spring 312 to be slightly elongated (approximately150.%) Frangible seam portion 310 b has not yet ruptured.

In FIG. 4C continued downward directed force on gate 308 has caused evenfurther downward travel of the remainder of flange 306 and gate 308. Gap334 has now widened even further. Gate 308 has now rotated approximately6° and elastomer spring 312 has been elongated approximately 10%.Frangible seam portion 310 a has still not begun to rupture.

In FIG. 4D, the dynamics of the movement of gate 308 changes. Oncefrangible seam portion 310 b has ruptured, elastomer spring 312contracts and begins to pull the remaining portion of flange 306 aupward thereby closing gap 334. The elongation of spring 312 shrinks toapproximately 0.05° elongation and the angular orientation of gate 308shifts, moving from 6° in FIG. 4C to a level (i.e. 0°) orientation inFIG. 4C. However, as the left edge of gate 308 rises, the right edge ofgate 308 continues downward.

In FIG. 4D, cover C2 has completely reclosed and substantially resealedas both portions of the frangible seam 310 a, 310 b have reclosed. Theelongation of elastomer spring 312 has become zero (i.e., no elongation)and the angle of rotation of gate 108 has also become zero. Line 338 hasbecome coincident with horizontal reference line 330.

As stated hereinabove, in the formation process of elastomer springs(e.g., elastomer spring 112), elastomer shrinkage during the curingprocess creates an important gate closing bias in the spring. This biasis sufficient to support the weight of a severed gate and hold that gatefirmly in a tightly closed position. A typical shrinkage during curingis approximately 0.05%, a seemingly small amount but sufficient toprovide the necessary force to hold a severed gate in a tightly closedcondition. It will be recognized that elastomer raw materials havingdifferent curing shrink rates may be chosen for different spring designsand placements. Consequently, the invention is not considered limited toa particular cure shrinkage rate. Rather, the invention is intended toinclude any suitable cure shrinkage rate in addition to theapproximately 0.005% chosen for purposes of disclosure.

It be recognized that operation of the opening and self-reclosing ofgate 308 as shown in FIGS. 4A-4D and described in the attendingdescriptions is controlled by the design of cover C1. The primarycontrol over the function of gate 308 is the material chosen forelastomer spring 312. In this example, an elastomer having a maximumpercentage of elongation of 150% has been chosen. In FIG. 4B, themaximum elongation is reached. Consequently, no further downward travelof the left edge of gate 308 is possible and the downward directed force332 is transferred to the right edge of gate 308 thereby causingfrangible seam portion 310 b to rupture. As the right edge of gate 308is freed, elastomer spring 312 immediately begins contracting and beginspulling the left edge of gate 308 upward until the right edge of gate308 finally returns to approximately its unopened position and frangibleseam portions 310 a, 310 b are closed.

If a material with a higher percentage of elongation (i.e., >200%) hadbeen chosen, the downward travel of the left edge of gate 308 could havebeen deeper into an interior region of the container to which cover C2was attached. The greater downward travel could have allowed splashingof the container contents.

This performance is achieved by the choice of elastomer, specificallythe percentage of elongation.

Referring now also to FIG. 5A, there is shown a side elevational,cross-sectional, schematic view of a cover having an internal elastomerspring in in accordance with the invention; generally at reference C3.

Cover C3 is shown before attachment to a container, not shown, and in asealed (i.e., unopened) state. Further, cover C3 is a simplified designused to illustrate the operation of the elastomer spring. More complexcovers using other elastomer springs are described and discussed in moredetail hereinbelow.

Cover C3 consists of a panel 526 (best seen in FIG. 5D) surrounding acentral gate or dome 508. Panel portions 502 a, 502 b have respectivedistal ends 504 a, 504 b that are adapted for attachment to upstandingwalls 518 a, 518 b of a container and adapted to form a peripheral seal,not shown between upstanding walls 518 a, 518 b and respective distalends 504 a, 540 b of seaming panel 502 a, 502 b, respectively. Note thatany container or portion thereof shown or discussed herein forms no partof the present invention and are shown and/or discussed only to betterdescribe cover C3. While in the cross-sectional view of FIG. 5A, seamingpanel portions 502 a, 502 b, distal ends 504 a, 504 b, and panelportions 520 a, 520 b are labeled for purposes of discussion, cover C3is typically a circular structure best seen in FIG. 5D and seaming panel502, distal end 504 and panel 520 represented respectively thereby arecontinuous, circular structures, at least until initial opening of gate508.

Distal ends 504 a, 504 b of seaming panel portions 502 a, 502 b,respectively form what is commonly known in the industry as a curl.Proximal ends, not specifically identified, of seaming panel portions502 a, 502 b each terminate in respective countersinks 516 a, 516 b. Inturn, sloped panels 520 a, 520 b are connected to respective tri-foldseparable seams forming flanges 506 a, 506 b. Flanges 506 a, 506 b areshown in detailed portions 522 a, 522 b in FIGS. 5B and 5C,respectively, and are discussed in more detail hereinbelow.

A gate or dome 508 occupies the central region of cover C3 surrounded bypanel 526 (FIG. 5D). Dome 508 in the simplified cover C3 occupiesapproximately 80% or more of the top surface of cover C3. It will berecognized that the novel construction may be implemented in gate ordome 508 ranging in size from substantially 100% of the cover surfacedown to very small size apertures.

Panel sections 526 a, 526 b surrounded by countersinks 516 a, 516 b andfill the space between countersinks 516 a, 516 b and gate 508.

An elastomer spring 512 is disposed on a lower (i.e., internal) surfaceof panel 526 a and attached both to the lower surface of panel 526 a andto a lower portion of flange (i.e., the portion beyond frangible seam510 a). Spring 512 provides support and closure force for gate 508 afterthe gate has been opened.

Referring now also to FIGS. 5B and 5C, there are shown enlarged drawingsof portions 522 a, 522 b of flanges 506 a, 506 b respectively. Ofparticular interest is the coined frangible seam 510 a, 510 b formed inflanges 506 a, 506 b. Frangible seam 510 a, 510 b defines a tear linecompletely around gate 508 that allows separation of gate 508 from panel526 as gate 508 of cover C3 is “opened”. Frangible seams 510 a, 510 bare typically formed using a coining process. However, it will berecognized by those of skill in the art that alternate formationprocesses may be utilized.

Referring now also to FIGS. 5D and 5E, there are shown top planschematic and partial side perspective schematic views, respectively ofcover C3 of FIGS. 5A, 5B, and 5C. In FIGS. 5D and 5E, the relationshipof each of the components and features described hereinabove withrespect to FIGS. 5A, 5B, and 5C may readily be seen. The width of gate508 is represented by arrow 528. In FIG. 5E, the relationship ofinternal elastomer spring 512 to the remainder of the structure of coverC3 may readily be seen.

Referring now also to FIGS. 6A-6E, there are shown a series of sideelevational, cross-sectional, schematic views of the cover having aninternal elastomer spring 512 of FIG. 5A in various stages of openingand self-closing. Table III provides, a percentage of elongation ofinternal elastomer spring 512 and an angle of rotation of gate 508relative to a horizontal reference line 530 connecting an upper point offrangible seam points 510 a, 510 b. Angle of rotation is indicated byreference number 538.

TABLE III Figure % Elongation Angle of Gate Rotation FIG. 6A 0.0% 0°FIG. 6B  50% −10° FIG. 6C 20 0° FIG. 6D 0.0% 9° FIG. 6E 0.0% 0°

In FIG. 6A, a downward directed force pressure exerted on gate 508 asshown by arrow 532 has not yet been sufficient to rupture frangible seam510 a, 510 b. Horizontal reference line 530.

In FIG. 6B, a sufficient downward directed force 532 has been exerted ongate 508 and, in response, frangible seam 510 a has ruptured and theremainder of flange 506 a has moved downward carrying a left edge ofgate 508 downward into what would be an interior region of a container,not shown, to which cover C3 would be attached. Reference number 534denotes the gap between the edges of frangible seam 510 a. As may beseen by the relationship of lines 538 and reference horizontal line 530,Gate 508 has rotated approximately −10°. This motion has caused internalelastomer spring 512 to be slightly elongated (approximately 50%).Frangible seam portion 510 b has not yet ruptured.

In FIG. 6C, continued downward directed force 532 on gate 508 has causedfurther downward travel of the remainder of flange 506 a and gate 508.Consequently, gap 534 has widened. Frangible seam 510 b has now rupturedand gate 508 is floating freely constrained only by elastomer spring512. Gate 508 is now substantially horizontal (i.e., 0° rotation) but isnow moved downward into what would be an interior of a container towhich cover C3 would be attached. The continued downward movement hasfurther elongated internal elastomer spring 512 by approximately 20%.

In FIG. 6D, frangible seam 510 b has ruptured and the remaining portionof flange 506 b has traveled downward as indicated by gap 538. Asinternal elastomer spring 512 contracts, the left end of gate 508 hasrisen and gap 534 has been reduced. Internal elastomer spring 512 hasstarted to contract in FIG. 6C and is now completely contracted (i.e.,at 0.0% elongation).

In FIG. 6E, cover C3 has completely reclosed and substantially resealedas both portions of the frangible seam 510 a, 510 b have reclosed. Theelongation of internal elastomer spring 512 has become zero (i.e., noelongation) and the angle of rotation of gate 508 has also become zero.Line 538 has become coincident with horizontal reference line 530. Anupward directed source provided by internal elastomer spring 512 nowholds gate 508 in a tightly sealed position.

In the examples of elastomer springs 112, 312, 512, it is assumed thatthe springs may be formed and/or cured in situ. In a high speed canfilling and sealing operation, such in situ placement and curing of anyelastomer spring may be impractical.

Referring now also to FIG. 7A, there is shown a side-elevational,schematic view of an external flush elastomer spring 700 for that may bepre-extruded and cured and then machine-applied to a container cover.Spring 700 has a roughly triangular shape with a left adhesive-receivingsurface 702 a and a right adhesive-receiving surface 702 b.

A slit 704 is disposed in the left side of spring 700 below a lower edgeof left adhesive-receiving wall 702 a. Slit 704 leads to an open centralarea 706 from an outside surface, not specifically identified, of spring700.

A flange receiving region 708 is disposed adjacent a hook tip 724.

Referring now also to FIG. 7B, there is shown spring 700 of FIG. 7A withadhesive, shown schematically at reference numbers 710 a, 710 b appliedto respective left and right adhesive-receiving walls 702 a, 702 b.Adhesive 710 a, 710 b may be applied to spring 700 at the time thespring is manufactured. If adhesive 710 a, 710 b is applied when spring700 is manufactured, an optional protective coating, not shown, may beplaced over adhesive 710 a, 710 b to prevent drying of the adhesive orprevent contaminating debris from clinging to the tacky surface ofadhesive 710 a, 710 b. In alternate embodiments, adhesive, not shown,may be applied to specific areas of a container cover prior to placingspring 700 into place. This may be accomplished using a variety ofmaterials and techniques believed to be well known to those of skill inthe art.

Referring now also to FIGS. 7C-7L, there are shown a series of partialside elevational, cross-sectional, schematic views of a portion of acontainer cover having elastomer spring 700 installed. The depictedcover portions each show a portion of a gate 712 and a portion of asurrounding panel 714. Also shown is a tri-fold seam or flangerepresented by reference number 718. A frangible seam 716 is placed ingate portion 712.

As seen in FIG. 7C, elastomer spring 700 is sized and configured to fitbetween outer portions of gate 712 and panel 714 so that the elastomerspring's top surface, not specifically identified, is substantiallyflush with the gate 712 and surrounding panel 714 to which elastomerspring 700 is attached. As may readily be seen, left and right adhesivereceiving surfaces 702 a, 702 b of a non-elongated elastomer spring 700conform to respective surfaces, not specifically identified, of gate 712and surrounding panel 714, respectively.

In FIG. 7D, a downward directed force 720 applied to gate 712 causesgate 712 to move downward, thereby stretching elastomer spring 700. Asmay be seen, central open area 706 and flange engaging region 708 areboth compressed.

As seen in FIG. 7E, continued downward force 720 causes further downwardtravel of gate 712 with consequent further elongation of elastomerspring 700. As seen in FIG. 7E, central open area 706 and flangeengaging region are both now almost completely compressed.

As seen in FIG. 7F, continued downward force 720 causes further downwardtravel of gate 712 with consequent further elongation of elastomerspring 700. The elongation of elastomer spring 700 allows flangeengaging region 708 to slide past bottom 718 of the tri-fold flange andflange engaging region 708 is positioned for toggle mode.

As seen in FIG. 7G, as elastomer spring 700 relaxes, flange engagingregion 708 is pulled upward to encircle and retain bottom 718 of thetri-fold flange. Once region 708 of elastomer spring 700 is in thisposition, the so-called toggle mode for the container top is set.

As seen in FIG. 7H, once region 708 of elastomer spring 700 is in theposition seen in FIG. 7G, elastomer spring 700 continues to exert anupward force on the flange, represented by bottom of flange 718. Becauseelastomer spring 700 is not compressible, the force caused by itscontraction separates frangible seam 716 and forms a gap 728. Once gap728 is formed, the contents of the container (e.g., soda, beer, etc.)may be oscillated or swirled in the container so as to put pressure 726on the inside of gate 712.

In FIG. 7I, gate 712 continues its upward movement and gap 728 opensfurther as elastomer spring 700 continues to contract to its originalposition as seen in FIG. 7C as the oscillated container contentscontinue to push against gate 112 (i.e., generates upward directed force726).

In FIG. 7J, once flange engaging region 708 is clear of bottom of flange718 of the tri-fold seam, elastomer spring 700 again supplies the upwarddirected force 722 that continues to move gate 712 upward.

And in FIG. 7K, elastomer spring 700 snaps back into its extruded shapeand gap 728 closes.

Finally, in FIG. 7L, gate 712 is returned to a closed position therebyeffectively re-sealing the contents of the container.

Referring now also to FIG. 8A, there is shown a side elevational,cross-sectional, schematic view of another elastomer spring, generallyat reference number 800. Elastomer spring 800 is intended as an internalspring for a cover C4 having a toggle mode.

Elastomer spring 800 has a body 802 divided generally into an upper bodyportion 804 and a lower body portion 806. Body 802 has a hole 808disposed therein.

An elongated tail 810 proceeded from lower body portion 806. A slot 812separates tail 810 from upper body portion 804.

Upper body portion 804 has a flange-receiving area 814 on a right sidethereof.

Elastomer spring 800 is formed such that tail 810 provides a counterclockwise (CCW) bias attempting to always exert an upward, CCW force ona lower surface of gate 826.

Referring now also to FIG. 8B, there is shown a side elevational,cross-sectional, schematic view of a self-closing container usingelastomer spring 800 to provide the restorative force for the reclosing.

A gate or dome 826 is surrounded by a panel 838, shown as panel portions838 a, 838 b in the cross-sectional view of FIG. 8B. As seen in FIG. 8E,panel 838 is a continuous circular structure. Intermediate gate 826 andpanel 838 is a trifold seam or flange 824, also shown as seam or flangeportions 824 a, 824 b. Flanges 824 a, 824 b include frangible seam 828a, 828 b that separates gate 826 from panel 838.

Panel 838 is connected to countersinks 830 that are, in turn, connectedto panel 832, again shown as panel portions 832 a, 832 b. Panel 832 is,in turn, connected to seaming panel 820, shown as seaming panel portions820 a, 820 b having respective distal ends 822 a, 822 b.

Elastomer spring 800 is fitted against a lower surface of panel portion838 a and fastened thereto with adhesive 846 best seen in FIG. 9A.Spring tail 810 is fastened to a lower surface of gate 826 with adhesive848, also best seen in FIG. 9A.

Referring now also to FIGS. 8C and 8D, there are shown detailed partialviews of flange portions 824 a, 824 b respectively at reference numbers834 a, 834 b.

Referring now also to FIG. 8E, there is shown a top plan, schematic viewof the container cover of FIG. 8B. The relative positions of all thestructures discussed in conjunction with FIGS. 8A-8B may readily beseen. In addition, the width of gate 826 is shown by arrow 840.

Referring now also to FIG. 8F, there is shown a partial side perspectiveview of the cover of FIGS. 8B-8E.

Referring now also to FIG. 8F, there is shown a bottom, perspective,schematic view of the cover of FIG. 8E.

Referring now also to FIG. 8G, there is shown an enlarged detail of aportion of the cover of FIG. 8F.

Referring now also to FIG. 8H there is shown a partial side perspective,cross-sectional, schematic view of the cover of FIG. 8A.

Referring now also to FIGS. 8I-8M, there are shown a series of sideelevational, cross-sectional, schematic views illustrating fivesequential steps involved in opening and subsequently re-closing gate826 of the container cover.

In FIG. 8I, the cover is unopened. A horizontal reference line 842 showsthat both sides of frangible seam 828 (i.e., frangible seam portions 828a, 828 b) as well as both edges of gate 826 are at the same elevation orlevel. A downward directed force represented by arrow 844 has not yetbeen sufficient to rupture frangible seam 828 a.

In FIG. 8J, downward directed force 844 has caused the rupture offrangible seam, at least frangible seam potion 828 a. The left edge ofgate 826 has dropped causing primarily the spring tail portion 810 ofspring 800 to be elongated and reference line 842 has an upward sloperelative to flange portion 824 a.

In FIG. 8K, continued downward pressure 844 has now caused frangibleseam portion 828 b to rupture and gate 826, while substantiallyhorizontal, has now been pressed downward into the container, not shown,to which the cover is attached. It should be noted that spring tail 810is still significantly elongated.

In FIG. 8L it may be seen that once frangible seam portion 828 bruptures, spring tail 810 contracts pulling the left edge of gate 826upward until frangible seam portion 828 a is reclosed. Note that theright edge of gate 826 is still downwardly depressed and reference line842 now has a downward slope relative to frangible seam portion 828 a.

Finally, as seen in FIG. 8M, the restoring force provided by a relaxingelastomer spring 800 has caused the right edge of gate 826 to be raisedto substantially its original, unopened position and frangible seamportion 828 b is reclosed.

FIGS. 8G-8K have illustrated a five step “see-saw” sequence for theinitial opening of the container using elastomer spring 800. Onceinitially opened and re-closed, the container may repeatedly be openedand reclosed. With the design of elastomeric spring 800, the containercover may be operated in a so-called toggle mode.

Referring now also to FIGS. 9A-9F, there are shown detailed sideelevational, cross-sectional, schematic views of the flange region of acontainer top in various stages of opening and closing, including atoggle mode (FIG. 9D) wherein gate 826 is retained in a fully open stateuntil deliberately oscillating (e.g., swirling) the container contentsto force gate 826 out of the toggle mode lock.

In FIG. 9A, adhesive regions 846 and 848 may be seen adhering elastomerspring 800 to panel region 838 a and gate 826. Although not clearlyshown in FIG. 9A, frangible seam 820 a has been previously ruptured(i.e., the container opened) and gate 826 has returned to a self-closedposition as shown. The CCW bias discussed above is applied to gate 826by spring tail 810 as indicated by arrow 850. The constant upward forceprovided by the CCW bias holds gate 826 in a closed position as shown.

In FIG. 9B, a downward force 844 against gate 826 causing downwardmovement of gate 826 with the subsequent deflection of spring tail 810.Downward pressure 844 overcomes the CCW bias built into elastomer spring800. Bottom of flange 824 a rotates toward flange receiving portion 814of elastomer spring 800 for eventual capture and retention thereby.Additional CCW arrow 844 shows a second region of CCW rotation and/orCCW bias force development.

In FIG. 9C, continued downward pressure 844 causes additional downwardmovement of gate 826 and deflection of spring tail 810. Pivot point 852around which gate 826 rotates has shifted to a point near the bottom offlange portion 828 a. Flange 824 a has rotated almost into flangereceiving portion 814 of elastomer spring 800. Rotation of gate 826 isnow around a new pivot point 854 best seen in FIG. 9E). At this point ofrotation of gate 826, flange 824 a is almost captured by flangereceiving region 814 of elastomer spring 800.

In FIG. 9D, the rotation of gate 826 in response to continued downwardpressure 844, seam receiving region 814 of elastomer spring 800 hascompletely captured and retained flange 824 a. Spring tail 810 ismaximally deflected and because of the angle of gate 826, the force ongate 826 retains flange 824 a in flange receiving portion 814 ofelastomer spring 800. As long as no external force is applied, gate 826is held open.

In FIG. 9E, an internal force 860 applied against the inside surface ofgate 826 forces flange portion 824 a out of flange receiving region 814.Such an internal force is typically generated by oscillating (e.g.,swirling, etc.) the contents of the container so as to splash or sloshthe contents against the inside surface of gate 826.

In FIG. 9F, once flange 824 a is released from flange receiving portion814 of elastomer spring 800, the restoring force provided by contractionof elastomer spring 800, particularly spring tail 810, in cooperationwith any continued oscillation of the container contents, brings gate826 upward toward its initial position as shown is FIG. 9A.

Referring now also to FIG. 10A, there is shown a top plan view of acover designated C5 having a center domed external elastomer hinge 1000that is so-called “manufacturing center registration compliant.” Thedesign shown in FIG. 10A allows an offset gate 1014 larger than theopenings possible with center rivet designs of the prior art. Inaddition, the size and placement of center domed external elastomerhinge 1000 interacts well with the upper lip 1042 (FIG. 10K) of aconsumer 1040 (FIG. 10L) drinking from the container, not specificallyidentified, to which cover C5 is attached. This process is bestillustrated in FIG. 10K.

Referring now also to FIG. 10B, there is shown a side elevational,schematic view of the cover of FIG. 10A. The center domed externalelastomer hinge 1000 is attached to both gate 1014 and surrounding panel1010 by adhesive 1022, readily seen in FIG. 10B. Also visible in FIG.10B are flanges 1012 a, 1012 b and frangible seam 1016 a, 1016 b.Reference number 1024 identifies a section of cover C5 shown in FIG.10B.

Referring now also to FIG. 100, the area identified by reference number1024 in FIG. 10B is shown in more detail.

Referring now also to FIG. 10D, there is shown a perspective view ofcover C5.

Referring now also to FIG. 10E, there is shown the side elevational,cross-sectional, schematic view of cover C5 but attached to containersides 1026 a, 1026 b with a respective crimp 1028 a, 1028 b. Neithercontainer sides 1026 a, 1026 b nor crimps 1028 a, 1028 b form any partof the present invention but are shown merely to show cover C5 in itsintended operating environment.

Referring now also to FIGS. 10F-10J, there are shown a series of sideelevational, cross-sectional, schematic views of cover C5 in variousstages of being opened and subsequently self-closing after opening.

In FIG. 10F, cover C5 is shown prior to initial opening.

In FIG. 10G, in response to downwardly directed forces shown as arrow1030, frangible seam 1016 a has ruptured and the left edge of gate 1014has moved downward. In the process of moving downward, a gap 1034 isformed. Note that frangible seam 1016 b has not yet ruptured. Ahorizontal reference line 1032 is provided to indicate the angle of gate1014 relative to its original, closed position.

In FIG. 10H, in response to continued downwardly directed forcerepresented by arrow 1030, gap 1034 has possibly widened slightly andfrangible seam 1016 b has now ruptured creating a right gap 1036. Gate1014 is lower than its original position (i.e., the position in FIG.10F) and appears to be approximately parallel to horizontal referenceline 1032.

With the frangible seam 1016 represented by frangible seam 1016 a, 1016b, completely ruptured, the center domed external elastomer hinge 1000,previously elongated and otherwise stretched from its original shape asseen in FIGS. 10G and 10H, begins to return to its original shape. Asshown in FIG. 10I, the restorative force provided by the return of hinge1000 to its original shape exerts an upward force shown as arrow 1038and the left side of gate 1014 is pulled upward closing gap 1034.

Finally, as seen in FIG. 10J, the right side of gate 1016 is also pulledupward to close gap 1036. The gate 1014 has now self-closed and thecontainer is effectively resealed.

Referring now also to FIG. 10K, a partial schematic view of a face 1040representing a consumer of the contents of the container is shown.Another useful feature of center domed external elastomer hinge 1000 isthat it is placed on the cover in a location that the upper lip 1042 ofconsumer 1040 contacts while drinking from the container. Becausefrangible seam 1016 has previously been completely ruptured as describedhereinabove, a gentle pressure by upper lip 1042 of consumer 1040succeeds in pressing gate 1014 of cover C5 inward, thereby allowingliquid or other content, neither shown, through the opening 1044 incover C5.

Since other modifications and changes varied to fit particular operatingrequirements and environments will be apparent to those skilled in theart, the invention is not considered limited to the example chosen forpurposes of disclosure, and covers all changes and modifications whichdo not constitute departures from the true spirit and scope of thisinvention.

Having thus described the invention, what is desired to be protected byLetters Patent is presented in the subsequently appended claims.

What is claimed is:
 1. A self-closing cover for a container, comprising:a) an openable gate disposed in said container cover, said gate beingsurrounded by a frangible seam; b) a panel surrounding said frangibleseam; c) an elastomer spring having a first portion affixed to said gateand a second portion affixed to said surrounding panel; whereby, inresponse to an externally applied downward force on an outer surface ofsaid gate, said frangible seam is ruptured thereby freeing said gatefrom said surrounding panel and moving at least a portion of said gatedownward, and upon removal of said externally applied downward force,said elastomer spring returns said gate to its original closed positioneffectively resealing said container cover.
 2. The self-closing coverfor a container as recited in claim 1, wherein said gate has a geometriccenter, said geometric center being disposed in one of the locationsselected from the group: coincident with a center of said containercover, and non-coincident with a center of said container cover.
 3. Theself-closing cover for a container as recited in claim 2, wherein saidelastomer spring is disposed on one of the locations selected from thegroup: on said external surface of said container cover, and on saidinternal surface of said container cover.
 4. The self-closing cover fora container as recited in claim 1, wherein said container cover isconfigured to receive said externally applied, downward force proximatea central portion of said gate.
 5. The self-closing cover for acontainer as recited in claim 4, wherein said container cover isconfigured to receive said externally applied, downward force deliveredby a heal of a palm of a person's hand.
 6. The self-closing cover for acontainer as recited in claim 2, wherein said container cover comprisesan external surface disposed outside a container when said containercover is attached to that container, and an internal surface disposedinside that container when said container cover is attached to thatcontainer.
 7. The self-closing cover for a container as recited in claim5, wherein said elastomer spring is disposed in one of theconfigurations selected from the group: an external top buttonconfiguration, an external chuck wall configuration, an internalconfiguration, and an external flush configuration.
 8. The self-closingcover for a container as recited in claim 1, wherein said elastomerspring is formed and cured in one of the locations selected from thegroup: in situ, and external to said cover.